Which, in connection with a mid-sized convertible, would be entirely forgivable. Brand allure counts for a lot to your typical fashion-conscious cabrio buyer, after all – a lot more than the Vauxhall badge counts for. But those who can see past such things will find a well-judged, adroitly tuned, skillfully executed new car here – one that definitely rewards a bit of enlightened thinking.

Value for money is at the heart of the car’s appeal. Although it’s based on the same platform that underpins the sixth-generation Astra hatchback, the Cascada is, in fact, a D-segment drop-top for the price of a C-segment model.

That means you get four adult-sized seats and a reasonable boot of up to 350 litres, but you only pay as much as you would for a Volkswagen Golf-sized premium-brand ragtop typically offering notably less everyday usability.

Practicality looks like the wrong weapon with which to lure convertible buyers away from the German brands, who tend to be shopping for second cars anyway. But in actuality, when you slide into the Cascada’s sensibly sized cabin, you do begin to visualise all the ways you’d get more use out of the car than you expected to.

Shame, then, that Vauxhall/Opel’s interior designers don’t quite have the flair, the ambition – or the budgets – of their counterparts at Audi. The Cascada’s cabin is perfectly functional and the car’s well-equipped, but – in spite of the adoption of a slightly broader colour palette than the Griffin norm – it’s a slightly dowdy, uninspiring fascia to look at.

Equipment levels are generous though, even on the entry-level SE trim. Primarily it features air-con, 18-inch alloys, a DAB tuner, Bluetooth connectivity, cruise control, rear parking sensors, an aux-in port and a USB connection, as well as the OnStar concierge, telematics and wi-fi system. Range-topping Elite models come with additional kit that includes dual-zone climate control, heated electric sports seats with leather trim, wind deflector and automatic lights and wipers.

The Cascada’s suspended via MacPherson struts and a torsion beam – but neither’s an ordinary example of the breed. At the front, the car uses Hiperstrut chassis technology borrowed from Vauxhall’s Insignia VXR, intended to reduce the impact of driving forces on steering precision, while at the rear the Cascada’s Watt’s Link suspension makes for more subtle tuning potential, and a much smoother ride.

Engine options include 138bhp 1.4-litre and and either 168bhp or 197bhp 1.6-litre turbocharged petrols, and just the one diesel, a 163bhp 2.0-litre CDTi. All drive the front wheels through six-speed manual or automatic gearboxes.

For all that promising chassis technology, the Cascada isn’t exciting to drive. It’s geared for relaxed, economical cruising, sprung for comfort and refinement – and it’s quite large and heavy.

All of which means its performance is seldom extraordinary, and its handling is tidy and accurate enough at normal speeds, but lacks grip and poise when you up the Cascada's pace.

But we’d argue that’s exactly as the Vauxhall Cascada should be. Bigger wheels and higher spring rates would likely only illicit flexing and shuddering from the car’s body – which, as it is, seems stiff and robust – and more stressed engines might fall short of the high standards the car sets on economy and mechanical refinement.

The engines are all adequate, but the higher-output motors haul along the Cascada’s bulk more effortlessly. The 163bhp oil-burner seems quiet for a diesel and has plenty of mid-range torque.